Not a stupid question at all.
The OS doesn't really matter as long as you have the things installed that you need installed. Your using Apache, PHP, and MySQL and all of those deal with whatever OS they're installed on, so it's not your problem.
Have a look here:
How to set up a local testing server for Dreamweaver
If you setup Dreamweaver to use relative paths instead of absolute paths you won't have to change a thing. I develop on Windows, test locally, and upload to a Linux server without changing anything. You might need a different connection file for the remote MySQL but that's about it.